Formation and control of magnetic vortex chirality in patterned micromagnet arrays

We have succeeded in developing highly ordered magnetic vortices in dense arrays of microstructured magnets and in evaluating individual spin configuration by employing a high-precision spin-imaging technique. High-definition pictures reveal fundamental properties of the ordered vortices, such as stability and interaction of vortex chirality. We have also demonstrated control of the chirality with the use of a magnetic field gradient but without introducing geometric asymmetry in the magnet shape. A simple control mechanism is deduced from micromagnetic simulations. (C) 2008 American Institute of Physics.